Modern escalators and moving walkways are constructed on trusses which support all of the components of the conveyors. In most cases with such escalators and the like which have glass balustrades, the balustrade mounts, which are generally clamps mounted on the truss, provide the locus for properly positioning the other components of the escalator, such as the decks, skirts, steps, handrail guides, and the like. Typically, the skirts and decks will be located relative to the balustrade mounts by means of brackets, spacers, or other means which are fixed to the balustrade mounts, and which may also be fixed to the skirts and/or decks, or merely abut the latter. In these types of escalators, the skirt panels are the vertical panels which directly flank the steps, and the deck panels are the panels which extend from the balustrades toward and which overlap the skirt panels. Care must be taken to ensure that both the deck and skirt panels are properly positioned relative to the steps, and that the desired positioning is maintained. Since these panels are sheet metal, they can be deflected away from the steps, and such deflection must be prevented.
U.S. Pat. No. 3,991,877 granted Nov. 16, 1976 to J. K. Kraft, et al; U.S. Pat. No. 4,159,758 granted Jul. 3, 1979 to I. C. Courson; U.S. Pat. No. 4,646,907 granted Mar. 3, 1987 to K. Streibig, et al; and U.S. Pat. No. 4,842,122 granted Jun. 27, 1989 to A. D. Van Nort are illustrative of typical deck and skirt mounting installations for escalators and moving walkways of the types which include glass balustrades. It will be noted that these assemblies all include brackets which are fixed to the balustrade mounts, and which engage the inner surface of the deck panels to properly position them relative to the steps. These inner brackets must be properly aligned before the deck is put in place, or else repeated corrective action must be taken until the decks are properly positioned. Also, when the deck panels are removed, the spacer brackets remain behind on the balustrade mounts, and present obstructions for servicing of the interior of the deck areas. These brackets limit tool accessibility and can cause hand injuries to escalator mechanics and service men. The brackets themselves will not be removed from the balustrade mounts except in rare cases, because to do so requires repeating the alignment process over again so that the decks can be properly replaced.
The U.S. Pat. No. 4,842,122 to Van Nort discloses a deck spacer which is as described above, and it also discloses a skirt spacer which is positioned just above the treads of the steps, and which is accessible from the step side of the skirts. The spacer allows one to set and adjust the position of the skirts, and thus the gap between the skirts and steps from the step side of the escalator after the skirts have been positioned on the truss. The spacer includes an internally threaded cylindrical piece which is welded to the internal skirt bracket; and a set screw which is threaded into the cylindrical piece, and which carries a washer that engages the inner surface of the skirts, i.e., the surface of the skirts which faces away from the steps. The set screws are accessible through openings in the skirts so that an Allen wrench or the like can be used to turn the set screw so as to move the washer toward or away from the steps. This will cause movement of the skirt toward or away from the steps so that an appropriate skirt-step gap can be established. So long as the washer maintains its position, and the set screw does not thereafter turn, the preferred gap will be maintained.
This skirt adjustment system is an improvement over the prior art systems which could not be accessed from the outside of the escalator, but it still has its shortcomings. This system still must be set up with the step skirts off of the escalator, it still is fixed to the interior brackets on the escalator, and it requires that the set screws and the skirt openings remain in alignment, or else it can't be used. This need for relatively perfect alignment means that the positioning of the cylinders, which are welded to the brackets must be very accurately accomplished so as to match the spacing between adjacent openings in the skirts. Another shortcoming of the Van Nort structure is that it does not provide any solution to the problem of properly positioning the deck panels, which still use the bulky fixed internal brackets.